if (typeof window.onload == "function") {    //判断之前是否有windows.onload
	var saved = null;                        //创建一个保存器
	saved = window.onload;                   //把之前的window.onload赋值
}

window.onload = function() {
	saved();  //第一个onload
}

function getFetch(url ,current , pageSize){
	let u = url+'/'+current+'/'+pageSize;
	fetch(url)
}